This invention relates to sugar-free, dry mix cellulose ether bulk laxative compositions.
It has been long known that cellulose ethers, such as carboxymethylcellulose and methylcellulose are effective bulk laxatives. The cellulose ethers relieve constipation by increasing the bulk of the stool, increasing the water content of the stool, and it is believed, by a lubricating effect on the stool.
Previously, cellulose ethers have been administered as bulk laxatives in the form of tablets, powders, and suspensions in highly concentrated sugar solutions. Each of these methods of administration has significant disadvantages which have limited the acceptance of these products by consumers.
Tableted cellulose ethers, for example, do not readily dissolve in the digestive tract because these cellulose ethers are highly hygroscopic. The outer portion of the tablet quickly forms a gel-like hydrate which prevents break up of the tablet and greatly retards hydration of the interior portions of the tablet. Accordingly, the tablet is often excreted as an intact soft gel mass. Although some laxative effect is produced by such gel masses, the cellulose ether is most effective when dispersed uniformly throughout the stool. Thus, when employed in tablet form, cellulose ethers have reduced efficacy as bulk laxatives.
Cellulose ethers have also been administered as powders, which powders are swallowed by the patient. Such powders often exhibit the same type of gelation as tablets, i.e., the individual particles lump together and remain partially undissolved as they pass through the digestive tract. Moreover, administration of cellulose ethers in powder form has caused nausea, cramping, and vomiting in some patients. Accordingly, cellulose ethers are not advantageously administered in powder form.
Cellulose ethers have also been administered as bulk laxatives as suspensions of the cellulose ether in water containing high concentrations of sucrose or other sugars and a flavoring. The sugar competes with the cellulose ether for the available water, thereby preventing the cellulose ether from hydrating sufficiently to form gels. The administration of cellulose ethers in such form has the advantage that the cellulose ether is sufficiently dispersed that it does not form significant amounts of lumps in the digestive tract. Unfortunately, however, such suspensions are very thick and semi-gelatinous. As such, they are visually unappealing. More significantly, due to their slimy mouth feel and extreme sweetness, such suspensions are quite unpalatable. Accordingly, such cellulose ether suspensions have not gained significant consumer acceptance.
Accordingly, a cellulose ether composition useful as a bulk laxative, which composition is palatable and not visually displeasing and which is administered without the formation of significant amounts of lumps or gels was developed.
Citrucel.RTM. Orange, a bulk forming laxative containing methylcellulose as its active ingredient, was first introduced into the market in 1986. This product contains 15 g of sucrose in the 19 g adult dose which corresponds to a 2 g dose of methylcellulose. To reduce the high sugar content of this product, a natural flavor formula lower in caloric content and containing only 1 g of sucrose was developed and introduced as a line extension in 1988. However, it was still desirable to produce a sugar-free bulk laxative composition, which is essentially sugar-free and thus virtually calorie free (it will be noted that the dispersing agent used herein, namely maltodextrin, has a few calories, namely 4 calories per gram). A major problem in doing so, however, was that the sugar component acted not only as a sweetening agent, but also as a dispersing agent as well.